Rivet-pulling gun



June 14, 1966 R. J. REEvE ETAL RIVETPULLING GUN Filed Feb. 26, 1954 um. wm. Nm. NN Sm ma/Afp @HE-2% BY @0265 .KA/04H United States Patent() 3,255,675 RIVET-PULLlNG GUN Richard .1. Reeve, 239 W. Dexter St., Covina, Calif., and George I. Noah, 14208 Demblon St., Baldwin Park,

Calif.

Filed Feb. 26, 1964, Ser. No. 347,455 Claims. (Cl. 91-466) This invention relates to a gun for pulling the stems of blind rivets to set such rivets and for pulling operations, generally, where the member being pulled is ruptured from the device of which it is a part.

An object of the present invention is to provide a pulling gun in which all actions, after the operation-instituting trigger thereof is pressed, are pneumatically carried out, such actions, by Way of example, comprising creation of forces that seal the operating valve, producing the power stroke of the gun, and causing return of the trigger to initial, non-operated position.

Another object of the invention is to provide lappulling gun, as above characterized, that is of small, compact size and yet is enabled to provide yan increased Working force without a commensurate increase of pneumatic p.s.i. increase.

A further object of the invention is to provide a pneumatic pulling gun that 'has an operating valve of simple and efcient design to eliminate the faults inherent in ring-sealed valves and sleeve-type valves ordinarily used in prior pneumatic pulling guns.

This invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The invention also comprises novel `details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description, 'and which is based on the accompanying drawing. However, said drawing merely shows, and the following description merely describes, one embodiment of the present invention, which is given by way of illustration or example only.

In the drawing, like reference characters designate similar parts in the several views.

FIG. l is a partly broken front elevational view of a rivet-pulling gun according to the present invention.

FIG. 2 is ia longitudinal sectional view as taken on the line 2-2 of FIG. l.

FIG. 3 is an enlarged cross-sectional view as taken on the line 3-3 of FIG. 2.

FIG. 4 is a similarly enlarged view showing the end of the handle of the gun that is secured to the gun body, the view being taken on -a plane immediately beneath the plane of the line 3-3.

The gun that is illustrated comprises, generally, a pistoltype handle l5 that is provided with a longitudinal compressed air passage 6; a slide valve assembly 7 mounted in the upper end of the handle to control ow from the passage 6; a body 8 connected to the upper end of said handle 5 and receptive of compressed air from passage 6, as controlled by the valve assembly '7; `a gang-type piston unit 9 operative in said body 8 and including a drawbolt 10 extending from the front or forward end of the body; and buier means 111 disposed within the body to absorb the shock of rupture of a rivet stem connected to the drawbolt.

The handle 5 is shown at its lower end with compressed Y air inlet 15 adapted for connection to an air hose. The

upper end of the handle is provided with a at face 16 that is flanked by extensions 17 along the opposite sides of the handle. The air passage 6 comprises a bore 18 that extends from the inlet 15 toward the face 16, and a 3,255,675 Patented June 14, 1966 ice A generally rectangular recess 19 into which said bore opens and which opens on said surface. A transverse bore 20 in the handle extends through the lower portion of the recess 19, is open at the forward edge of the handle, and is closed at 2-1 inwardly adjacent to the -rearward edge of said handle. A sealing ring 22 set into the face 16 encircles the recess 19.

The slide valve assembly 7 is shown as a trigger 23 in the form of a plunger slidingly tted in the bore 20 and provided with a push end 24 on the outer end of said plunger, a sealing ring 25 around said plunger to seal against air leakage 'from the open end of the bore 20, and a slide valve 26 guided in the recess 19 and carried by the plunger 23. Since there is no seal provided between the closed end of bore 20 and the plunger 23, the sliding t of said plunger in said bore end aifords air passage from the bore 18, past said plunger, into the bore 20 between the inner end of the plunger and the closed end of the bore 20.

The valve 26 is shown as a seat 27 that has an extension pin fitted in a cross bore in the plunger 23, and a resilient seal block 28 mounted on said seat and provided on its upper face with a bypass recess 29. The seal seat 427 and seal block 28 slidingly yfit the recess 19, are of lesser length than the length of said recess so the same may be slid toward the right from the position shown, upon finger pressure applied to the trigger end 24. The total height of the valve seat and seal block is such that the top face of said block is flush with the `face 16 of the handle, the bypass recess 29, of course, being depressed below said face 16.

The body'8 is shown as a tube 30, the bore 3:1 of which is smooth to constitute a cylinder, a back cap 32 closing one end of said bore, a front wall 33 held in place by a retaining ring 34, and a partition wall 35 held in place by retaining rings 36 and 37 and dividing the bore 31 into a front cylinder 38 and a back cylinder 39. The back cylinder is vented through a port 40, and sealing rings 41 around the periphery of the walls 33 and 35 seal against the bore 31.

The body tube 30 is provided with a flat face 42 that has ilatwise engagement with the face 16 of the handle and is in sealing engagement with the ring 22 set into said face 16. Since said ring 22 encircles the open end of the recess 19 and is in sealing contact with said face 42, the same prevents leakage from said recess between faces 16 and 42. Set screws 43 xedly -connect the body and handle, as shown in FGS. 1 and 3, and engage as above described.

As best shown in FIGS. 2 and 3, two ports 44 and 45 are provided in said yface 42, the same opening on the recess 29 of the seal block 2'8, said recess thereby constituting a bypass between said ports in the projected position of the slide valve assembly 7, as shown in the drawing. A passage 46 is connected to the port 44, an extension 47 of said passage opening in the front end of the front cylinder 38 immediately rearward of the wall 3-3, and an extension 48 of said passage opening in the front end of the back cylinder 39 immediately rearward of the partition wall 35. A passage 49 is connected to the port 45 and an extension 50 thereof comprises a vent to atmosphere. A passage 51 is provided to communicate the recess 19 with the cylinder 38 adjacent the partition wall 35.

The piston unit 9is shown as a piston 52 operating in the cylinder 38, a piston 53 operating in-the cylinder 39, and a connection 54 between said pistons and extending axially through the partition wall 3S.

The drawbolt 10 is shown as a `forward extension of the connection 54, the same passing forwardly through the axis of the wall 33. The tool ordinarily provided on said drawbolt is not shown since the same comprises no part of this invention.

l 22 may have any other shape desired, including round.

Also, that the valve operates within the area encompassed by the ring and -has a floating lit in the recess 19.

Operation The passage 6, including its recess 19, the passage 51, and the front cylinder 38 between the piston 52 and the wall 35, are filled with pressure air. Both ports 44 and 45 being connected by the bypass recess 29, the space 56 between the wall 33 and the piston 52, and the space 57 between the wall 35 and the piston 53, are both Vented to atmosphere through the passages 46, 49 and 50. This is the normal unoperated condition of the gun.

After engaging the tool on the end of the drawbolt with a rivet stem, the end 24 of the trigger is pushed by a a finger of the h-and gripping the handle 5l toward the closed end 21 of the bore 20. The valve seat 27 and seal block 28, carried by the trigger, are shifted to the right to engage against the right end wall of recess 19 to limit this movement. Now, the port 44 is` opened to the pressure air in the passage 6, and the port 45, through the bypass recess 29, is opened to the cylinder 38 by AWay of the passage Sl. to vent said cylinder through passages 49 and 50.

With the trigger thus depressed, pressure air from port 44 enters passage 46 and its extensions 47 and 4S to supply pressure air to the spaces 56 and 57 which had been vented before the trigger was depressed. Thus, both pistons 52 and 53 are affected by the air pressure simultaneously, so that the total air pressure on both pistons is `effective as the power exerted on the drawblock 10. Upon rupture of the stem being pulled by the drawbolt, the piston unit 9 is suddenly released, causing the same to strike the buffer means 11. Even though the trigger may be still depressed, the pulling operation ceases, since the spaces 56 and 57 and all passages leading thereto are filled with air at the inlet pressure thereof.

The above maintains until the trigger end 24 is released, at which time the pressure differential between ambient air pressure on the outer end of the trigger and the line pressure in the bore between its inner end and the inner end of the trigger projects the trigger, re-shifting the same and the valve assembly 7 to initial position, in which the spaces 56 and 57 are vented and the cylinder 38 fills with pressure air to cause projection of the piston unit 9 to the position of FIG. 2, ready for the next pulling operation.

The simplicity of construction and operation of the present puller gun are deemed to be evident from the foregoing description thereof, and it appears that the same fully realizes the objects of the invention as set forth in the preamble to said description.

While the foregoing has illustrated and described what is now contemplated to be the best mode of carrying out the invention, the construction is, of course, subject to modification without departing from the spirit and scope of the invention. Therefore, it is not desired to restrict the invention to the particular form of construction illustrated and described, but to cover all modifications that may fall within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. A rivet-pulling gun comprising;

(a) a body having two axially aligned cylinders,

(b) a piston unit comprising two gang-connected pistons, one in each cylinder, a drawbolt on said unit extending from an end of the body,

(c) -a pistol grip handle secured to said body, provided with air-pressure passages including a recess open at the end of the handle that is secured to the body,

(d) a slide valve assembly carried by said handle and comprising a push-type trigger member guided in said handle, 4and a slide valve affixed to said member and movable in the mentioned recess, and

(e) passages in the body controlled by said slide valve in one position thereof to vent said-cylinders on the sides thereof open to the sides of the pistons that, when subjected to air pressure, cause retracted pulling movement of said unit, and a passage to supply a pressure ow to one of said cylinders on the side thereof open to the side of the piston therein that returns the unit to projected position and, in the other position of the slide valve, vents said one cylinder side and provides pulling air pressure to the first-mentioned sides of the two pistons,

(f) said slide valve comprising a block having an elongated recess therein and the passages in the body having two adjacent ports that are in communication with each other across said recess in the mentioned one position of the slide valve, the pressure-applying passage being in communication with one of said ports across said recess in the mentioned other position of the slide valve.

y2. A rivet-pulling gun according to claim 1, including a sealing ring encircling the recess in the handle and in sealing engagement with the surface of the body against which the mentioned block is slidin'gly engaged.

3. In a rivet-pulling gun having a pistol grip handle that fixedly mounts a body having two aligned cylinders provided With an operating piston unit for creating a pulling force,

(a) said handle having passages for compressed air that include an elongated recess open to the face of the lbody to which the handle is affixed,

(b) said body having air passages extending to said cylinders and including two ports and a passage in aligned rel-ation,

(c) a slide valve assembly carried by said handle and comprising a push-type trigger member guided in said handle, and a slide valve affixed to said trigger and movable in the mentioned recess,

(d) said slide valve assembly including a sealing block having a bypass recess and being slidably engaged in said recess in the handle and movable between a position in lwhich the bypass recess communicaates the two ports to vent the passages in the body, and a position in which the bypass recess communicates one of said ports and the mentioned aligned passage in the body to conduct pressure air from the passages in the handle through the passages in the body to said cylinders in the body.

4. In a rivet-pulling tool having a pneumatically operated pulling power unit that is normally vented, said tool being provided with a pistol grip handle connected to a body having a cylinder with an operating piston therein to move said operating unit,

(a) said handle having passages for compressed air that include an elongated recess open to the face of the body to which the handle is axed,

(b) said body having air passages extending to said cylinder and including two ports and a passage in aligned relation and directed toward the recess in the handle,

(c) a slide valve assembly carried by said handle and comprising a push-type trigger member guided in said handle, and a slide valve atiixed to said trigger and movable in the mentioned recess,

(d) said slide valve assembly including a sealing; block having a bypass recess and being slidably engaged in said recess in the handle and movable between a position in Iwhich the bypass recess communicates the two ports to vent the passages in the body, and a position in which the bypass recess communicates one of said ports and the mentioned aligned passage in the body to conduct pressure air from the passages in the handle through the pas- 5 sages in the bodyV to said cylinders in the body, and (e) an O-ring encircling said recess in the handle to seal around the recess against leakage therefrom and vfrom said passages at the connection between the handle and the body. 5. A rivet-pulling tool according to claim 4 in which the slide valve has a oating t with the trigger in the elongated recess.

References Cited by the Examiner UNITED STATES PATENTS 2,354,841 8/1944 Shaff 92-151 2,661,599 12/1953 Folmer 92--151 SAMUEL LEVINE, Primary Examiner. FRED E. ENGELTHALER, Examiner. P. E. MASLOUSKY, Assistant Examiner. 

1. A RIVET-PULLING GUN COMPRISING: (A) A BODY HAVING TWO AXIALLY ALIGNED CYLINDERS, (B) A PISTON UNIT COMPRISING TWO GANG-CONNECTED PISTONS, ONE IN EACH CYLINDER, A DRAWBOLT ON SAID UNIT EXTENDING FROM AN END OF THE BODY, (C) A PISTOL GRIP HANDLE SECURED TO SAID BODY, PROVIDED WITH AIR-PRESSURE PASSAGES INCLUDING A RECESS OPEN AT THE END OF THE HANDLE THAT IS SECURED TO THE BODY, (D) A SLIDE VALVE ASSEMBLY CARRIED BY SAID HANDLE AND COMPRISING A PUSH-TYPE TRIGGER MEMBER GUIDED IN SAID HANDLE, AND A SLIDE VALVE AFFIXED TO SAID MEMBER AND MOVABLE IN THE MENTIONED RECESS, AND (E) PASSAGES IN THE BODY CONTROLLED BY SAID SLIDE VALVE IN ONE POSITION THEREOF TO VENT SAID CYLINDERS ON THE SIDES THEREOF OPEN TO THE SIDES OF THE PISTONS THAT, WHEN SUBJECTED TO AIR PRESSURE, CAUSE RETRACTED PULLING MOVEMENT OF SAID UNIT, AND A PASSAGE TO SUPPLY A PRESSURE FLOW TO ONE OF SAID CYLINDERS ON THE SIDE THEREOF OPEN TO THE SIDE OF THE PISTON THEREIN THAT RETURNS THE UNIT TO PROJECTED POSITION AND, IN THE OTHER POSITION OF THE SLIDE VALVE, VENTS SAID ONE 